<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="box">
        <section>
            <div></div>
        <div></div>
        <div></div>
        <div></div>
        </section>
        
    </div>
</body>
<style>
    /* .box{
        width: 300px;
        height: 150px;
        background: yellow;
        display: flex;
        align-items: flex-end;
        justify-content: center;
    }
    .box div{
        width: 30px;
        height: 30px;
        border-radius: 50%;
        background: pink;
        margin: 10px;
    } */
    .box{
        width: 300px;
        height: 150px;
        background: yellow;
        text-align: center;
        position: relative;
    }
    .box section{
        width: 100%;
        position: absolute;
        text-align: center;
        bottom: 0;
        font-size: 0;
    }
    .box div{
        width: 30px;
        height: 30px;
        border-radius: 50%;
        background: pink;
        display: inline-block;
        font-size: 16px;
        margin: 10px;
    }
</style>
</html>